Quando ele viu seus pais morrerem, ele era jovem demais para entender a morte.
Quando bebê, Harry não entendia que seus pais foram mortos. Mesmo quando ele começa a se lembrar mais à medida que envelhece, ele só lembra como um flash de luz verde no início, e não entende o que aconteceu. Mais tarde, ele vê mais claramente como o Lorde das Trevas matou seus pais, mas entender retrospectivamente a morte pode não ter sido suficiente para ver os Thestrals.
“He couldn’t remember being in the car when his parents had died. Sometimes, when he strained his memory during long hours in his cupboard, he came up with a strange vision: a blinding flash of green light and a burning pain on his forehead. This, he supposed, was the crash, though he couldn’t imagine where all the green light came from. He couldn’t remember his parents at all.” - Harry Potter and the Philosopher's Stone, Chapter 2 (The Vanishing Glass)
Além disso, ele não viu Quirrell morrer.
Harry ainda estava lutando com Quirrell quando ele desmaiou por causa da dor que sua cicatriz estava causando a ele.
“Quirrell screamed and tried to throw Harry off – the pain in Harry’s head was building – he couldn’t see – he could only hear Quirrell’s terrible shrieks and Voldemort’s yells of ‘KILL HIM! KILL HIM!’ and other voices, maybe in Harry’s own head, crying, ‘Harry! Harry!’ He felt Quirrell’s arm wrenched from his grasp, knew all was lost, and fell into blackness, down … down … down …” - Harry Potter and the Philosopher's Stone, Chapter 17 (The Man with Two Faces)
Quando Harry se levanta, ele ainda pensa que Quirrell tem a Pedra Filosofal.
“Harry stared at him. Then he remembered. ‘Sir! The Stone! It was Quirrell! He’s got the Stone! Sir, quick –’
‘Calm yourself, dear boy, you are a little behind the times,’ said Dumbledore. ‘Quirrell does not have the Stone.” - Harry Potter and the Philosopher's Stone, Chapter 17 (The Man with Two Faces)